Surgical device for connecting soft tissue

ABSTRACT

The invention comprises a surgical instrument including an external tube ( 2 ) and two elongated members ( 4 ) positioned in said tube ( 2 ), each of which includes a distal end ( 10   a ) for capturing one of the two tissue zones (M 1 , M 2 ) to be attached. The instrument ( 1 ) may further comprise a catching member ( 22, 25 ) for each tissue (M 1 , M 2 ) to be attached; a rod ( 15, 16 ) linked to each catching member ( 22, 25 ) enabling tension to move axially, said rod ( 15, 16 ) being separable from said catching member ( 22, 25 ) when a tension is exerted on it beyond a certain threshold; and a member ( 17   a ) forming a stop for locking axially each catching member ( 22, 25 ) during said tension.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a divisional of U.S. patent application Ser.No. 09/523,018 (Attorney Docket No. 020489-000300), filed Mar. 10, 2000,which was continuation of PCT/FR98/01960, which designated the UnitedStates, filed Sep. 12, 1997, the full disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] This invention provides a surgical device allowing thepercutaneous connection of two soft tissue areas that are ordinarilyseparate. This device is particularly intended for reconstruction ofheart valves, especially the mitral valve, and for the treatment of anymalformation of a heart septum.

[0003] In a condition known as mitral insufficiency, the mitral valvedoes not completely shut, and does not prevent the back-flow of blood tothe left atrium from the left ventricle. Surgical repair is thennecessary. In a current procedure, a sternotomy is performed. Thepatient is then placed under extra-corporal blood circulation while theheart is stopped, and the heart chambers are opened to gain access tothe mitral valve, usually through the left atrium. Once the mitral valveis accessed, repair procedures include annuloplasty and, more recently,suturing of the free edge of the anterior leaflet to the free edge ofthe back leaflet where the mitral insufficiency occurs.

[0004] These procedures are complicated and require general anesthesia,sternotomy and extra-corporal blood circulation. They also require highdoses of anti-coagulant therapy adding to the operative risk of amyocardial infarction and hemorrhage.

SUMMARY OF THE INVENTION

[0005] The methods of the present invention are performedpercutaneously, diminishing considerably these risks. A surgical deviceallows the connection of two zones of soft tissue that are usuallyseparate. In a particular embodiment, a connection is formed between afree edge area of an anterior mitral leaflet and a free edge area of aback mitral leaflet. Suitable surgical devices for performing tissueconnection are described for example in EP 558 031 and WO 94/18893, andmay comprise:

[0006] (a) a tube which may be inserted percutaneously until its distalextremity reaches the area around the tissues to be connected; and

[0007] (b) two elongated elements inside that tube, each of whichcomprises a distal extremity having a device that grasps one of the twotissues to be connected;

[0008] (c) wherein the distal extremities of these elongated elementsmay be opened and closed in order to permit introduction into thedesired area, allow the procedure.

[0009] Particular devices according to the present invention may furthercomprise:

[0010] (a) a grasping element, optionally having two parts for capturingeach of the tissues to be connected, wherein the grasping or hookingelement effects the connection of the two zones of tissue when broughtclose thereto by shifting of the portions of distal extremities to aposition where they meet;

[0011] (b) a rod connected to each of the grasping or hooking elementsand operated from the proximal end of the tube in order to axially shiftthe elongated element, wherein the rod can be separated from thegrasping or hooking element upon pulling beyond a given threshold; and

[0012] (c) a wedge inside the tube, allowing the axial immobilization ofeach grasping or hooking element while pulling on them.

[0013] The rod positions the insertion of the hooking element up to thelevel of the tissue edges to be connected. The rod also engages thehooking element against the wedge in order to open the two hookingparts.

[0014] According to the present invention, the device may be used toremotely grasp through a percutaneous passage, to draw together, and toconnect the two zones of tissue by a simple external manipulation.

[0015] Preferably, the tube, the elongated elements, and the rod areflexible enough to be inserted percutaneously and through a patient'svasculature for the treatment of the leaflets of a cardiac valve, inparticular the mitral valve. Each of the elongated elements is made outof an elastically flexible material, and one of these elongated elementsdiverges from the longitudinal axis of the other. The two elongatedelements can move axially in relation to the tube between (a) aretracted position within the tube where the ends of the elongatedelements are flexibly bent and closed together, and (b) a position wherethe ends of the elongated elements spring open and diverge from eachother in a way that permits those ends to capture the soft tissues inorder to grasp them.

[0016] The elongated elements may be deployed to allow their distalextremities to grasp the tissue areas or may be retracted in order tomake the insertion, shifting or removal of the apparatus easier. Eachelongated element may comprise a rod made of elastic material, with acurved distal extremity and/or a harpoon shape, and a sheath able toslide axially in a forward position to cover the distal extremity andslide back to uncover it.

[0017] According to a variation, each elongated element can be composedof a tube linked to a system that contracts its internal volume in orderto grasp the corresponding tissue area, and expands to release thetissue with no lesion. In this case, the wide-mouthed shape of theelongated element's distal extremity will insure a large enough graspingsurface.

[0018] Preferably, the device includes two hooking elements. One isoperated on the distal side of the tissues, and the other, to beoperated on the proximal side of the tissues, is situated between thefirst hooking element and the wedge element. This way the two hookingelements can be operated on both sides of the tissues and can be pressedtogether for a perfect attachment of those tissues.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For greater clarity, the invention is described again inreference to the enclosed Figures representing two unrestricted examplesof the invention in its optimal capacity.

[0020]FIG. 1 shows a longitudinal section of a heart with a mitral valvethat does not shut properly and has to be treated with this device.

[0021]FIG. 2 shows the mitral valve before treatment.

[0022]FIG. 3 shows a mitral valve similar to FIG. 2 after treatment bysuture according to the usual procedure.

[0023]FIG. 4 is a view similar to that of FIG. 1, with the device of thepresent invention inserted into a heart.

[0024]FIG. 5 is an enlarged view of a longitudinal section of the distalextremity of the device.

[0025]FIG. 6 shows a view of this distal extremity according to the lineVI-VI of FIG. 5.

[0026]FIG. 7 and FIG. 8 are similar views to FIG. 5 at different stagesof the procedure.

[0027]FIG. 9 is a similar view to FIG. 2 of the mitral valve aftertreatment with the device.

[0028]FIG. 10 is a view of this valve according to line X-X of FIG. 9.

[0029]FIG. 11 illustrates an alternative embodiment of the device of thepresent invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0030]FIG. 1 shows a heart C with a mitral valve M having poorly opposedleaflets (M1, M2). Thus, the valve M does not shut tightly and no longerperforms its back-flow function between the left atrium O and the leftventricle V. According to conventional procedures, after sternotomy, thepatient is placed under extra-corporal blood circulation. The heart isstopped and the heart chambers are opened to directly reach to the valveM and stitch together the free opposite edges of both leaflets (M1, M2)as shown on FIGS. 2 and 3. Connecting leaflets M1 to M2 restores a goodattachment between them and restores the imperviousness of valve M.

[0031] FIGS. 4 to 5 show a device (1) according to the present inventionwhich enables the percutaneous connection of leaflet M1 to leaflet M2.This device (1) comprises an external tube (2), guidewire (3), twoelongated elements (4), and a clipping system (5). The apparatus issufficiently flexible to be percutaneously inserted into the heart C,through the patient's vascular, e.g., the Vena Cava Ve and theintra-atrial septum S. Guidewire (3) is inserted through valve M and sothe distal extremity of external tube (2) is located in the left atriumO, with its distal opening facing mitral valve M.

[0032] Each of the elongated elements (4) has a distal extremity (4 a)that is normally curved to diverge outwardly. A rod (10) is made out ofa relatively rigid but still elastic material, more particularly inmetal, with a sheath (11) of synthetic material. The distal extremity(10 a) of the rod (10) is sharp and more or less harpoon-shaped. Thesheath (11) fits on the rod (10) and can slide axially to a forwardposition (as shown on left side of FIG. 5) in order to cover the distalextremity of the rod, and can slide back (as shown on the right side ofFIG. 5) in order to uncover that same distal extremity (10 a). Theelongated elements (4) extend from the end of the tube (2). Because ofthis, they can be shifted axially in relation to the tube (2) between aretracted position where the extremities (10 a) close together (FIG. 7and 8) and an extended position where these same extremities (10 a)diverge from each other (FIG. 5). The clipping system (5) comprisesthree concentric tubular rods (15, 16, 17) that can be slidablyintroduced over the guidewire (3). Each rod can also slide axially inrelation to the others. The internal rod (15) is linked to a disk (20)through a frangible area (21). The rod and disk (15 and 20) are made ofmolded synthetic material. The disk (20) is axially pierced in order tolet the guidewire (3) pass through, and carries a clip (22). Side prongs(22 a) of that clip extend from the proximal face (20 a) of the disk(20). A central portion (22 b) of the clip (22) having a central ringfor receiving the guidewire (3) is embedded into the material of thedisk (24).

[0033] The intermediate rod (16) is also connected by a frangible area(23) to a disk (24) with two clips (25). Side prongs (25 a) of theseclips extend from the distal face (24 a) of this disk (24), and centralportions of the prongs are embedded into the material of the disk (24).On each side, the disk (24) has two diametrically opposed notches (26,FIG. 6) to allow the passage of the elongated elements (4). The externalrod (17) has an expanded distal extremity (17 a) which engages theproximal face of the disk (24). Each of these rods (15, 16, 17) can beextended beyond the proximal extremity of tube (2) so they can beshifted by the operator.

[0034] A handle or other structure for manipulating the rods (15, 16,17) will usually be provided at a proximal end of the device. The handlewill permit deployment rod (15) while rod (17) is held in a desiredposition in relation to tube (2), and then deployment rod (16), whilerod (17) is also held in the desired position in relation to tube (2).

[0035] In practice, under X-ray or echography control, the guidewire (3)is first inserted through Vena Cava Ve, the intra-atrial septum S, andmitral valve M. Then tube (2) and its internal parts are inserted intothe Vena Cava Ve and through the septum S until the distal extremity oftube (2) is directed at mitral valve M (FIG. 4). At this stage, disk(20) should be held at the opening of tube 2 (FIG. 5), while elongateelements (4) are retracted so that their distal extremities areretracted into slots (26).

[0036] When the distal extremity of tube (2) is in the proper position,rod (15) is shifted to advance disk (20) beyond leaflets M1 and M2 andinto the left ventricle V. Elongate elements (4) are then advanced totheir extended positions, as shown in FIG. 5. As the elongate elements(4) are advanced, their distal extremities diverge. After the elements(4) are advanced, distal extremities (10 a) of rods (10) are positionedclose to leaflets (M1, M2). The sheaths (11) of elements (4) are thenretracted in relation to the rods (10) in order to uncover theextremities (10 a), each of which can then pierce and capture theadjacent leaflet M1 or M2. Tube (2) is then advanced over the elongateelements (4), drawing the distal extremities (4 a) closer, as shown onFIG. 7. This action draws the free edges of leaflets M1 and M2 together.

[0037] Rod (17) is advanced distally in relation to tube (2), and rod(15) is pulled proximally in relation to tube (2) in order to insert theprongs (22 a and 25 a) of clips (22 and 25) into the leaflets M1 and M2.The tension on rod (15) forces the prongs (22 a and 25 a) against theopposed walls (20 a, 24 a) of the disks (20, 24) and breaks frangiblearea (21). This break gives the prongs of the clips enough freedom ofmovement to ensure a good connection between leaflets M1 and M2. Thesheaths (11) are then advanced distally in relation to the rods (10) toengage leaflets (M1, M2). This facilitates the extremities (10 a) of therods from the leaflets (M1, M2). Rod (16) is then pulled while holdingrod (17) in position to break frangible area (25). Leaflets (M1, M2)have thus been clipped to each other by their free edges, as shown inFIG. 9 and 10.

[0038]FIG. 11 shows a variation of the apparatus where rods (10) andsheaths (11) have been replaced by two catheters (40) having trumpeteddistal extremities (40 a). These catheters (40) project beyond theproximal end of tube (2) and may be attached to syringes that permit thecreation of negative pressure. The grasping or releasing of leaflets(M1, M2) is then achieved by controlling the internal pressure withincatheters (40). The trumpeted ends (40 a) ensure a sufficient grip onleaflets (M1, M2). Those ends (40 a) are preferably sufficientlyflexible enough to bend slightly when they are drawn between the wall oftube (2) and two lateral slots (26) of disk (20). The other parts ofthis alternative device are the same as already described and bear thesame record numbers.

[0039] It goes without saying that the invention is not limited to theabove example and is opened to different variations. For instance, theunstressed shape of the extremities (10 a) that hook the tissues couldbe of a curved J which is straightened when drawn into the sheaths (11).The elongated parts (4) and the connecting system could also be placedin separate tubes. The device (1) could be inserted arterially as wellas veinously.

What is claimed is:
 1. A system for performing cardiac valve repair,said system comprising: an external tube suitable for introducingthrough a patient's vasculature and into a chamber of a heart, said tubehaving a central lumen and a distal opening; and a pair of elongateelements extensible from the distal opening of the tube, wherein eachelement is adapted to capture a leaflet of the valve.
 2. A system as inclaim 1, wherein the elongate elements are spring-biased to divergeoutwardly when advanced distally relative to the external tube.
 3. Asystem as in claim 2, wherein each elongate element has a distalextremity adapted to capture a valve leaflet.
 4. A system as in claim 3,wherein the distal extremity of each elongate element as a harpoon-liketip.
 5. A system as in claim 3, wherein the distal extremity of eachelongate element as a vacuum-applying tip.
 6. A system as in claim 1,wherein the elongate elements are further adapted to draw the leafletstogether after they are captured.
 7. A system as in claim 6, furthercomprising apparatus which attaches the leaflets together when saidleaflets are drawn together by the elongate elements.
 8. A system as inclaim 7, wherein the apparatus which attaches the leaflets togethercomprises a clip-applying apparatus.
 9. A system for performing cardiacvalve repair, said system comprising: an external tube suitable forintroducing through a patient's vasculature and into a chamber of aheart; and a clipping system including a first element adapted to bebrought up beneath a pair of valve leaflets and a second element adaptedto be brought down over the valve leaflets, wherein the leaflets arecaptured between the first and second elements and wherein the first andsecond elements may be left to clip free edges of the leaflets together.10. A system as in claim 9, wherein the first and second elements aredisks.
 11. A system as in claim 10, wherein at least one of the disksincludes prongs projecting toward the other disk.
 12. A system as inclaim 11, wherein the prongs penetrate leaflets held between the disks.13. A system as in claim 9, further comprising a pair of elongateelements extensible from a distal end of the external tube, wherein eachelement is adapted to capture a valve leaflet.
 14. A system as in claim13 wherein the elongate elements are spring-biased to diverge outwardlywhen advanced distally relative to the external tube.
 15. A system as inclaim 13, wherein each elongate element has a distal extremity adaptedto capture a valve leaflet.
 16. A system as in claim 15, wherein thedistal extremity of each elongate element has a harpoon-like tip.
 17. Asystem as in claim 15, wherein the distal extremity of each elongateelement as a vacuum-applying tip.
 18. A system as in claim 13, whereinthe elongate elements are further adapted to draw the leaflets togetherafter they are captured.